The PAR Rating system is an industry scale endorsed by The Carpet and Rug Institute and measures a carpet's likelihood to change from its original appearance due to matting. It is rated on a scale from 1-5, with a high number representing the least change and therefore higher quality. Generally, the denser a carpet is tufted, the higher its PAR will be.

Fiber
Fiber is a major component in determining a carpet's durability There are 5 basic fibers that are used in carpet construction, each with their strengths and weaknesses.

Nylon: One of the most popular pile fibers used. It is wear-resistant, resilient, withstands the weight and movement of furniture, and provides brilliant color. Ability to resist soil and stains. Generally good for all traffic areas.

Polyester: Noted for luxurious, soft "hand" when used in thick, cut pile textures. Has excellent color clarity and retention. Easily cleaned, and resistant to water soluble stains.

Polypropylene (Olefin): Strong, resists wear and permanent stains, and is easily cleaned. Resists static electricity and is often used in both indoor and outdoor installations because of its resistance to moisture and mildew.

Acrylic: Offers the appearance and feel of wool without the cost. Has low static level and is moisture and mildew resistant. Commonly used in velvet and level loop constructions.

Wool: Noted for its luxury and performance, wool is soft, has high bulk, and is available in many colors. Generally, wool is somewhat more expensive than synthetic fibers. And in some cases may aggravate allergies for some people.